Amid calls for reform in the Roman Catholic Church, Pope Benedict is making his first state visit to his native Germany, kicking off the four-day trip Thursday in the capital, Berlin.

The visit is controversial, with as many as 100 lawmakers planning to skip the pontiff's address to the lower house of parliament. German Interior Minister Hans-Peter Friedrich, a Protestant, criticized those who plan to boycott the speech for “arrogance, narrow-mindedness and provincialism.”

As many as 20,000 protesters are expected to turn out for the pope's speech to the German parliament in Berlin. Those expected at the demonstration will include gay and lesbian rights organizations and groups who want to see reform in the church – on issues including divorce, ordination of women priests, abolishing celibacy for clergy, and support for victims of sexual abuse by priests.

Germany's 50-million Christians are almost evenly divided between Protestants and Catholics, and many see the pope's visit as an opportunity to promote greater understanding between the two churches.

During his visit, the 84-year-old pontiff will hold masses in the capital and the cities of Erfurt and Freiburg. He also will meet with Chancellor Angela Merkel and President Christian Wulff.